Stoper drill with rotary impact attachment



Sept. 7, 1954 E. B. LEAR 2,688,258

' STOPER DRILL WITH ROTARY IMPACT mom-mm Filed March 51, 1955 3SheefiruSheet l INVENTOR 59a: 5. 54,?

ATTORNEY Sept. 7, 1954 R 2,688,268

STOPER DRILL WITH ROTARY IMPACT ATTACHMENT Filed March 31, 1953 3Sheets-Sheet 2 INVENTOR 484 5 154%.

ATTORNEY Sept. 7, 1954 E. B. LEAR STOPER DRILL WITH ROTARY IMPACTATTACHMENT 3 Sheets-Sheet 3 Filed March 31, 1955 INVENTOR BY W WATTORNEYa r lrllll. I 0." I I I I 7 t L U Patented Sept. 7, 1954 STOPER DRILLWITH ROTARY IMPACT ATTACHMENT Earl B. Lear, Utica, N. Y., assignor toChicago Pneumatic Tool Company, New York, N. Y., a corporation of NewJersey Application March 31, 1953, Serial No. 345,763

12 Claims. 1

This invention relates to drilling and bolting apparatus and moreparticularly, to a rock drill of the stoper type including an attachmentfor providing rotary impacts, such as would be useful Iion thetightening or loosening of threaded memers.

The stoper drill and attachment of the inven" tion will be foundespecially useful in a certain phase of mining operations, namely, theplacement of suspension roof supports. Much attention has recently beengiven to the use of suspension roof supports in tunnelling operations,especially in coal mines. Such a method of supporting a mine roof hasmany advantages over the conventional timbering method, not only fromthe standpoint of mining efiiciency and resulting economies, but alsofor the manner in which accident hazard is greatly reduced. Briefly, thesuspension roof sup port method comprises the use of metal rods whichare inserted in the tunnel roof and are anchored in areas which are notlikely to be stressed or disturbed in the tunnelling operations. Bearingplates, which are next applied to the exposed end of the rods, are drawntightly against the roof of the tunnel by means, such as nuts. Ifdesired, channel irons, which are held in position by several anchoredrods, can be substituted for the bearing plates, so as to give supportto a greater roof area. In this type of roof support many differentforms of anchor bolts have been devised. One common type of bolt, orstud, is a one inch rod, 4 to 6 feet long which is split on one endwhile the other end is provided with a thread to fit a standard nut.

The use of the stoper drill and rotary impact attachment of theinvention, provides a convenient means for the placing of suspensionroof supports, since the rock drill can be used for first drilling theholes for the rods, then after the rods have been anchored in the holes,the rotary impact attachment can be fixed to the drill and the nutsrunon the anchored rods so that the bearing plates or channel irons can bedrawn tightly against the tunnel roof. Hence, the need for two separatetools, i. e., a drill and an impact wrench, with separate power hoses orlines for each, can be eliminated, since the device of the inventionserves a dual purpose.

An object of this invention is to provide a stoper drill and rotaryimpact attachment for drilling and tightening operations, which willobviate the need for two separate tools, with their respective supplylines, for such drilling and tightening operations.

Another object of this invention is to provide a stoper drill and rotaryimpact attachment whereby the longitudinal impacts of the drill areutilized to produce a rotary impact motion in the attachment, fortightening operations.

A further object is to provide a stoper drill and rotary impactattachment, which will be found especially useful in the placementofsuspension roof supports in tunnelling operations.

A still further object is to facilitate release of the rifle barrotation in the stoper drill either for the purpose of starting a drillhole on the uneven surface of the rock, when interruption of rotation isdesirable, or for enabling the stoper drill to be converted readily intoan impact wrench. A feature of this invention is a ratchet ring providedwith notches on its periphery which are engageable with a locking deviceunder manual control.

Still another object of this invention is to provide 'a stoper drill androtary impact attachment, which is simple in design, convenient tooperate, economical from the standpoint of first cost and regular use,and of rugged construction and long life.

These and further objects of the invention will appear more apparentfrom a study of the following specification and related drawings, in

which:

Fig. l is a side elevation View of the stoper drill and rotary impactattachment of the invention;

Fig. 2 is an enlarged cross section of the drill as seen from line 22 inFig. 1, illustrating the rotation release mechanism;

Fig. 3 is a view of the top or front end of the drill as seen from line33 in Fig. 1;

Fig. 4 is an enlarged longitudinal section taken and the detentarrangement for yieldingly locking it in adjusted position;

Fig. 8 is a perspective view of a release pawl, as used in the stoperdrill of Fig. 1;

Fig. 9 is an isometric view of an end portion of a cam, as used in thestoper drill of Fig. 1;

Fig. 10 is an end view on a still larger scale of a rotary impactattachmentof the invention;

Fig. 11 is a longitudinal section view of the rotary impact attachmentof the invention, as seen from line H--!| in Fig.

Fig. 12 is a fragmentary section view illustrating a retaining pin usedin the rotary impact attachment of the invention, as seen from line|2-|2 inFig.1l;

Fig. 13 'isan isometric view of a portion of a rotation anvil, as usedin the rotary impact attachment of the invention;

Fig. 14 is a portion of an end. view of a housing used in the device ofFig. 11;

Fig. 15 is a fragmentary sectional view of the same as indicated by thearrows IS in Fig. 14;

Fig. 16 is a cross-section as" seen from line Iii-l6 in Fig. 11;

Fig. 17 is a cross-section as seen from-line ||l'| in Fig. 11;

Fig. 18 is ,a longitudinal view of a wedge type rod driver for use withthe1-drill of the invention.

Fig. 19 is a longitudinal sectional view taken through the drill of Fig.1, but with the drill arranged for drilling operations as shown in Fig.4, and is drawn in an enlarged scale.

Referring'now to the drawings, Fig. 1 illustrates a rock drill of thestoper type having a front-head portion 20, a cylinder or main bodyportion 2| and a backhead 22, all of which are secured together by draw'bolts 23 arranged on each side of the drill. The front head portion*supports a feed leg cylinder 24, which extends parallel to the axis ofthe drill, and contains a reciprocable piston 25, which is pointed atits lower or rearward extremity. A feed leg control-valve 26a arrangedwithin the body of the drill, is operated by handle means 26 to causeflow of compressed air into theforward end of the feed leg cylinder 24,via passageway 24a to force: piston 25 rearwardly, or out of thecylinder, which results in forward movement of the drill, assuming thatthe pointed end of the piston is abutting an immovable body, for examplethe flooriof the mine tunnel. A'handle 21, for carrying or supportingthe drill, may be aflixed there-' is shown in Fig. 4, and a rifle barhaving a helical splined portion, which engages the hammer piston. Therear end of the rifle bar has a head 3| containing pawls 32, which areresiliently maintained by spring loaded detents 32a to engage slots 330formed in a ratchet ring 33 supported in a cavity in' the backhead 22.As the piston 29 reciprocates, it is given a step-by-step rotation, dueto the helical connection between the piston 29 and rifle bar 30,operating in conjunction with the pawl and ratchet arrangement, all asis well known in the art. The intermittent rotative movements of thepiston are transmitted through a chuck 33a which has a splinedconnection with the piston and. which is mounted in the front head 20.The front end of the chuck has a bushing 33b arranged to support adrillsteel 34 non-rotatively in the chuck whereby the drill steel isarranged to partake of the step by step rotation of the piston. Anautomatic distributing valve 35a is arranged within the drill on anexterior. portion 35 of the main bodyportion 2|, and a throttle valve36, positioned in the backhead 22, is operable by handle means-31 toadmit compressed air from an air line. 38, to the automatic valve, whichdirects the air in a manner to cause the hammer piston 29 to reciprocatewithin the drill. A water tube 39 centrally arranged within the drill,is adapted to conduct water to the drill steel during drillingoperations, as is common practice in a drill of the s'toper type. An oilreservoir 4|, having a metering passageway arrangement 42, connectingwith a cavity containing the throttle valve 36, is provided for theadmission of minute particles of'oil to the live air for lubricating thedrill.

A rotation release arrangement is provided to permit selective operationthe rock drill without rotation of the drill steel 34. This rotationrelease arrangement includes a cam shaft 43 which is rotatably mountedwithin the backhead 22', the inner end of the shaft having a cam 44,which is adapted-to operate a pawl 45, slidably positioned within thebackhead. As seen in Fig. 8, the pawl 45 is of slablike proportions andhas a recessed section providing-a shoulder 46 on one side thereof.Ratchet ring 33' is adapted to rotate within the backhead, and has onits outer periphery a plurality of notches or slots 41. The pawl 45, inlocked position, is resiliently maintained sothat one end thereofengages one of the slots '41 of the ratchet ring. In such lockedcondition, the ratchet ring providesa rigid abutment for the pawls 32 tooperate against, resulting. in the step-by-step rotation of the piston29' and drill steel 34, as heretofore set forth. When the cam shaft 43is rotated 90 from the position shown in Figs; 2 and 5, the cam 44 byvirtue of engagement with shoulder 46 will maintain the end of pawl 45out of engagement with slots 41 of the ratchet ring 33. In such unlockedcondition the ratchet ring will be free to rotate or oscillate withinthe backhead and will not provide a rigid abutment for the pawls 32 tooperate against, hence, rotation of the drill steel will not occur.

ing theratchet ring 33, will oscillate as the hammer. piston 29 iscaused to reciprocate.

A handle 48 is keyed to the cam shaft 43 to provide for the convenientrotation thereof, and an indexing pin 49 is resiliently arranged to abutdetents formed on an exterior portion of the cam shaft, to maintain thelatter in either rotation releaselocked or unlocked condition.

The rotary impact attachment 28, as seen in Fig. 11, includes a housing50, which is threaded at one end to receive a housing cap 5|, and isadapted to surround and support for rotation, a ratchet ring 52 whichhas a square-sided extension 53. Positioned within the ratchet ring52-is a rifie'bar nut 54 which has four pawl members 55 equally spaced,the outer end of each being resiliently maintained, by rubber inserts 56or equivalent, in engagement with notches or teeth 51, arranged aboutthe inner surface of the ratchet ring 52. On the inner surface of therifle bar nut 54 are four spiral equi-spaced grooves 58; which areadapted to receive spline members 59formed on a head portion 6| of arotation anvil 62. The rotation anvil has a hexagonal shank'portion 63which extends through a hexagonal hole formed in the housing cap 5|, andis of length. sufficient to enter into the chuck bushing 33b in fronthead portion 20 of the drill, to engage with the hammer piston 29, inthe manner'of the drill steel 34.

A compression spring 64, centered at one end" in a cavity 65 formed inthe head portion El and at the other end in'a cavity 66 formed in theextension 53, urges the head portion 6| of the It will be seen that inthe latter con-- dition, the rifle bar and associated parts includ--rotation anvil 62 in the direction of the housing cap 5|. Affixed to theextension 53, is a driving head BI which has a shank portion 68 adaptedfor coupling with a removable socket 68a for engaging the nut or bolt tobe rotated. A rubber cushion 69 is maintained within the driving head Elfor absorbing the axial blows which occur in the use of the impactattachment during a nut tightening operation. The cushion thus serves toprevent shattering of the roof shale or rock surrounding the bolt hole.The driving head BI is maintained on the extension 53 by means of a pinH which extends through an elongated hole 12 formed in the extension 53,the ends of the pin H engaging holes in the driving head 61, as shown. Asplit metal band 13 is positioned within a groove formed on the exteriorof the driving head 51, to maintain the pin H in position. A lubricantconnection 14 is positioned in the ratchet ring 52 for the lubricationof the various movable parts included in the assembly.

At the threaded end of the housing 50 are arranged sixteen radial slots15, of the same width as seventeen radial slots Hi formed in a flanglike portion of the housing cap 5!.

A circumferential groove 11 is formed on the exterior of the housing 50and the flange-like portion of the housing cap 5|, to overlap the slotsI5 and It. A split metal band 18, having a hook '39 at one end, isarranged within the groove if so that the hook l9 enters into one of theslots 15 and 16. In this manner, the threaded connection between thehousing 50 and housing cap 5| is positively locked.

The housing cap at has a cylindrical projection 8! on the lower or rearside, which is of such proportions as to flt into a cavity 82 providedin the front head portion 20 of the drill. A pair of pins 83 arediammetrically arranged about the projection 8| of the housing cap 5|,in a manner as to engage recesses 84 formed in the front head portion20, as best seen in Fig. 3. The pins 83 and recess 84 arrangementprevent the rotary impact attachment 28 from turning after it is inposition on the drill.

It will be seen from a study of the arrangement of the rotary impactattachment 28 as described above, that with the assembly in position onthe drill, each blow of the hammer piston 29 of the drill, against theend of the shank 63 of anvil 52, will drive the anvil forward and therifle nut E i will be given a rotary motion, due to the splinedconnection between the latter two elements. This rotary motion will betransmitted to the ratchet ring 52, by virtue of the pawls 55 inengagement with the notches 5! of the ratchet ring, thus the drivinghead 67, connected to the ratchet extension 53, will be rotated, as wellas the socket which is afflxed thereto and which engages a driven nut.The reactive force of the anvil 62 acting upon the rifle nut 5 to causerotation of the ratchet ring 52, is transferred to the housing cap 5|,by the hexagonal shank 63 of the anvil 52 working in the hexagonal hole60, and then to the drill, by way of the pin 83 and recess 84arrangement between the rotary impact attachment and the ,front headportion 20, and is resisted by the operator of the drill, eithermanually or by flxing the drill in operative position. Upon completionof its forward thrust the anvil 62 is restored to its normal or rearwardposition by the compression spring 64. During such rearward movement thesplined portion 59 on the anvil rotates the rifle nut 54 in a directionopposite to that which occurred during the power stroke. Such backwardor restorative turning movement of the rifle nut is not transmitted tothe ratchet ring 52 or to the tool head 61 because of the disposition ofthe pawls 55 as will be apparent from Fig. 16. Thus, the rifle nut iscaused to oscillate in response to the reciprocations of the anvil, andduring each power stroke turns the ratchet ring through a distance equalto I, 2 or 3 ratchet teeth, depending on whether the nut fits tightly orturns freely on the bolt.

The rotary impact attachment 28 is shown for right-hand rotation; ifleft-hand rotation is desired, it would be necessary to provide partshaving a reverse slope of the anvil splines 59 and the mating grooves 58of the nut 54, as well as a change in the operative direction of thepawls 55.

When the drill is used for drilling operations, it is arranged as shownin Figs. 2 and 4, namely, the rotation release arrangement is locked,and the drill steel 34 is in position in the front head portion 20.

After the holes have'been drilled in the roof and the bolts driven andanchored therein, the drill is used for nut tightening operations. Forthis purpose it is then arranged as shown in Fig. 1, namely, the rotaryimpact attachment 28 is in position on the front head portion 20, withthe anvil 63 in the stoper chuck and the rotation release cam shaft 53,is turned so that the cam 44 is in position shown in Fig. 6. A washerplate 90 of suitable dimension, for example 8 inches square and 4 inchthick, is placed on the rod 86a together with a nut 9|. The rotaryimpact at tachment drives the nut extremely tight, thereby actuallybending the plate to conform to the uneven contour of the rough face ofthe roof rock.

While the impact wrench of the present invention is designed especiallyfor tightening or loosening nuts on roof support bolts in mines, it hasother applications, for example in the erection or dismantling of heavyequipment.

In Fig. 18 is shown a wedge type rod driver 85, which may serve as anauxiliary part in suspension roof support placement operations. Thedriver has a threaded portion 86 for engagement with the end threadedrod 86a to be anchored in the drilled hole, and a shank portion Bl,which is of cylindrical shape, and which is placed in the chuck bushing33b of the drill, in the manner of the drill steel 34. The impacts ofthe hammer piston 23 upon the end of the shank 8'5, quickly drives therod to anchored position within the roof tunnel hole.

What is claimed is:

1. In a device. of the character described, an assembly including areciprocable hammer piston arranged to deliver impact blows to anelement supported by the assembly, a rotation arrangement for rotatingthe supported element, means to disengage said rotation arrangement toprevent rotation of the supported element, and a rotary impactattachment connectable to the assembly for utilizing the impact blows ofthe hammer piston to deliver rotary impact blows.

2. In a device of the character described, an assembly including areciprocable hammer piston arranged to deliver impact blows to anelement supported by the assembly, a rotation arrangement for rotatingthe supported element, disengaging means operable to disengage saidrotation arrangement to prevent rotation of the supported element, and arotary impact attachment positionable in part within said assemblyand'adapte upon operation of. said disengaging means; to. utilize theimpact blows of. the hammer piston to. deliver rotary impact blows.

3. A device according to claim 2, wherein said rotary impact attachmentcomprises a housing arrangement adapted to be maintained, in, fixedposition relative said assembly, a first rotatable member supported bysaid housing arrangement and having an extension adapted to receivesocket means, a second rotatable member enclosed by the first rotatablemember and having a plurality of pawl members engageable with the firstrotatable member for rotary driving connection in a given direction, areciprocably arranged driving; element positioned in part within thehousing and having a portion adapted to receive impact blows and aportion having helical splines for engaging with grooves on the secondrotatable member whereby movement of the driving element in a forwarddirection as a result of an impact blow will cause rotation of thesecond rotat-- able member, and resilient means compressively. arrangedbetween the extension of the first rotatable member and the helicalsplined portion of the driving element.

4; A rotary impact attachment comprising a housing arrangement adaptedto be maintained in relatively fixed position, a ratchet ring rotatablysupported by said housing arrangement and having a plurality of notcheson an innerperiphery and an extension adapted to receive a socket means,a rifle bar nut arranged within the ratchet ring and having a pluralityof pawl members pivotally connected thereto a free end of each of thepawl members engaging the notches of the ratchet ring so that theratchet ring may be rotated in a given direction, an anvil memberpositioned in part within the housing for reciprocal movement and havinga shank portion adapted to receive impact blows and a portion havinghelical splines for engaging with grooves formed on an inner peripheryof the rifle barnut whereby movement or" the anvil member in a forwarddirection as a result of an impact blow will cause rotation of the riflebar nut, and a compression spring arranged between the ratchet ringextension and the helical splined portion of the anvil member.

5. A rotary impact attachment according to claim 4 wherein a cushioningmeans is positioned between the ratchet extension and the socket meansto absorb compressive shock resulting from an impact blow on the anvilmember.

6. A rotary impact attachment according to claim 5 wherein the housingarrangement includes a housing element and a housing cap elementthreadably connected therewith, and a looking arrangement formaintaining said elements in connected condition comprising a split ringwhich is positioned in a peripheral groove formed in part on each ofsaid elements, said ring having a hook; at one end which engages slotmeans:

formed in each of said elements.

is fixed against rotary movement with respect the housing cap.

8. A device according to claim 2, wherein the rotation arrangementincludes a rotatable rifle bar having a head portion carrying aplurality of pivoted pawl members, a rotatable member surrounding thehead portion and having a groove means on an inner and outer peripherythereof, said pawl members being resiliently arranged to engage groovesof the inner groove means.

9. A device according to claim 8, wherein the disengaging meanscomprises a disengaging pawl reciprocably arranged so that one endthereof can be moved into a groove on the outer periphery of therotatable member and prevent the latter from rotating, and a manuallyoperable cam arrangement for moving the disengaging pawl out ofengagement with a groove on said outer groove means.

10. In a stoper drill, a reciprocating hammer piston, a rotationmechanism for turning the piston and including a rifle bar having a headportion carrying a plurality of pivoted pawls, a ratchet ringsurrounding the head portion and pawls, and having notches on its innerand outer periphery, said pawls being resiliently arranged to engage thenotches on the inner periphery of the ratchet ring to permit relativerotation in one direction only between the rifle bar and ratchet ring,and means for disabling the rotation means to permit the hammer pistonto reciprocate ring, yieldable means for moving the disengaging pawltoward the ratchet ring, and a manually operable cam for moving thedisengaging pawl in the opposite direction in opposition to saidyieldable means.

11. A stoper according to claim 10, in which the disengaging pawl has aflat shape and is mounted for rectilinear movement in a directionapproximately tangent to the periphery of the ratchet ring.

12. A stoper according to claim 11, in which the disengaging pawl isrecessed to receive the operating portion of the manipulative cam.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,459,402 Johnson June 19, 1923 2,086,261 Douglass July 6,1937 2,263,736 Lear Nov. 25, 1941 2,271,803 Pfeiffer et al Feb. 3, 19422,300,392 Austin Nov. 3, 1942

